Target identification enhancement using a combination of linear sampling method and adjoint sensitivity analysis

This study describes a technique for complete identification of a two-dimensional scattering object using microwaves where the scatterer is assumed to be a homogenous dielectric medium. The employed technique assumes no prior knowledge of the scatter´s material properties like electric permittivity and conductivity, and the far-field pattern is used as the only primary information in identification. The hybrid approach proposed consists of initially retrieving the shape and the position of the scattering object using a linear sampling method and then determining the electric permittivity and conductivity of the scatterer using adjoint sensitivity analysis. The technique results in high computational speed, efficiency and stability. In addition, the technique can be generalised for any scatterer structure. Numerical results are used to validate the feasibility of the proposed approach.